1. Field of the Invention
The present invention relates to lens optical systems, and more particularly, to lens optical systems for compact camera modules that can be applied to cellular phones.
2. Description of the Related Art
Due to the recent convergence trends in appliances, cameras are converged to cellular phones, and the cellular phones mounted with cameras are widely supplied. Cellular phones have a compact, portable size and thus cameras to be converged to the cellular phones also need to be compact and show high performance at the same time.
In general, a lens optical system of a camera is formed of spherical glass lenses to obtain excellent optical performance, such as aberration correction, for example. When using a spherical glass to provide excellent optical performance, six or seven spherical glass lenses need to be used.
Also, high-quality images are realized due to the development of solid-state imaging devices, such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) image sensor, for example.
However, when six to seven spherical glass lenses are used, this large number of lenses is an obstacle to providing a compact size appliance, and the spherical glass lenses increase processing costs.
In addition, due to the characteristics of camera lenses, the size of lenses is sequentially increased toward an imaging device in order to secure a light path. The size of lenses affects the size of phone cameras, and thus the size of lenses needs to be reduced to match the size of subcompact cellular phones, and lenses having a high resolution and high performance need to be realized at the same time.